Method and apparatus for manufacturing pouches

Abstract

A method for manufacturing pouches made of at least partly thermoplastic material, including the steps of superimposing at least two webs of at least partly thermoplastic material, joining the webs at adhesion regions or lines, and cutting the webs at cutting regions or lines in order to provide pouches. In a condition in which the webs are superimposed, the method further includes the step of mutually aligning the webs by causing the elongation of at least one of the two webs via the application of heat.

The invention claimed is: 
     
       1. A method for manufacturing empty pouches made of at least partly thermoplastic material, including the following steps:
 a. superimposing at least two webs of at least partly thermoplastic material; 
 b. joining said webs at adhesion regions or lines; 
 c. cutting said webs at cutting regions or lines in order to provide empty pouches with an open mouth through which said empty pouches are configured to be filled, and 
 further including, after said step of superimposing the webs, the step of: 
 a1. in a condition in which the webs are superimposed, exerting a traction force on said webs and causing the selective elongation of at least one of the two webs via the application of heat, wherein said heat is applied to at least one of the two webs so as to mutually align said webs as result of said elongation and wherein said heat is applied before the step b. of joining the webs; 
 wherein said heat is applied by directing a stream of hot air onto the at least one of the two webs, and 
 wherein the stream of hot air is at a temperature comprised between 60° C. and 90° C. 
 
     
     
       2. The method according to  claim 1 , further including a step of checking an alignment of said webs, performed via optical detection of markers provided on a surface of said webs, and wherein the application of heat is controlled by the detection of a condition of misalignment of said markers.